My issue is on the business side. Why would anyone choose me - or even know it's an option - instead of someone professional? I can't just make a portfolio site and call it a day.
I'd appreciate some advice. I'm in the UK.
I later tried online forums where people where searching for programmers and had extremely mixed results but even back then there was competition from India that was cheeper. I did have a couple of jobs troubleshooting problems that the Indian programers “didn’t notice” and weren't interested in fixing after “finishing” the job (sort of understandable, do the minimum required and move on when you are the cheapest and don’t care about developing customer relations).
Overall you have a couple of points you can compete on. Price, speed, quality and availability/convenience. If you find your customers locally you’ll have availability/convenience covered. You will probably have to compete on price to begin with and you might want to make sure your customers know they are getting a special to build up your portfolio. Speed and quality are something you will have to prove yourself on and you don’t have a lot of control over however your customers see you will be how they recommend you (or not) to others that are searching for somebody.
Depending on if you more IT or design savvy you might want to expand your competences in one direction and build contacts in the other.
P.S.: I quit the self employment racket after a while but one of my friends still works like this nearly 20 years later.
If you've successfully made sites for yourself, then you don't need practice on the tech side ~ you need practice on the "dealing with clients" side. This is a skill-set hugely underappreciated by folks new to the field; you expect that the client knows what they want - _they don't!_, and part of your job is to suss it out of them. Sometimes clients will have no idea what they want until they see it, so you'll have to ideate and iterate for them.
And you'll need to be the one to level-set client expectations. Sometimes clients will ask the impossible of you. I've had clients essentially describe "The Next Facebook idea!" to me, but are only willing to pay $200. There's an old ClientsFromHell.net post that goes something like "Client: How much would it cost for visitors to my website to be able to log in by pressing their hand on the computer monitor? WebDev: Millions and Millions of dollars. Client: Well, I can see you're not serious about this...".
The "dealing with people" part is crucially important, for both providing a good product and for protecting yourself. Starting with Friends and Family is a great place to start and will help you build that skill-set.
I hate that this is the reality of the web right now but this is basically the reality of the web right now. Almost no one cares if you can make a phpbb forum and you could set it up correctly or whatever knowledge that you have is.
Create a site for your business to showcase what you've done and your capabilities. Sign up on sites that allow people to find freelance talent.
Create an account on LinkedIn and see if you can get others to write recommendations for you.